An air-conditioning system that includes a plurality of central controllers controlling a plurality of air-conditioning appliances and also includes a central management device that controls the plurality of central controllers is proposed (for example, refer to Patent Literature 1). In the air-conditioning system described in Patent Literature 1, the central controller includes a storage unit that stores collected data of air-conditioning appliances (operation data), and when the number of times of collection reaches a predetermined number, the central controller outputs the operation data to the central management device side.